Analysis of a novel human protein WDC146 highly expressed in testis : for elucidation of the function during spermatogenesis

1) WDC146是一种新的人蛋白，分子量为146 kDa，在睾丸中高表达。它由3个结构域组成，分别是一个WD40结构域、一个胶原样结构域和一个富含gpr的重复结构域，从n端到c端。2) WDC146在人和小鼠睾丸中均有高表达。氨基酸序列总体上具有显著的同源性（96%），其中WD40结构域区域完全匹配（100%）。即使在果蝇和酵母中，我们也发现了部分保守的序列。3) WDC146在粗线精母细胞中有明显表达，细胞内可见核和核周定位。4)对WDC146在精子发生过程中的表达模式的详细分析正在进行中，睾丸固定的技术难度适用于原位杂交。5) WD40结构域是蛋白-蛋白相互作用的平台基序。重复进行双杂交筛选以检测与WDC146的相互作用蛋白，但尚未成功。6)癌睾丸基因是睾丸特异性基因，在许多肿瘤和肿瘤细胞系中也有表达。WDC146可归为其中一类，因为所检测的肿瘤细胞系均显示中度表达WDC146，但部分肿瘤未表达WDC146。7) WDC146基因定位于2q14-21，由22个外显子组成。除了约4kb的完整mRNA外，错误剪接产生的嵌合mRNA总是在约1kb的大小上检测到。8)启动子区域位于外显子1上游0.5kb区域内。

1) WDC146 is a novel human protein of 146 kDa which is expressed highly in testis. It is composed of three domains, a WD40 domain, a collagen-like domain and a GPR-rich repeat domain, from N-terminus to C-terminus, respectively.2) WDC146 is highly expressed in testis both in human and mouse. The amino acid sequence showed significant homology between them overall (96%), including complete match (100%) for the region of WD40 domain. Even in Drosophila and yeast, we identified the sequence conserved in part.3) WDC146 showed marked expression in pachytene spermatocytes, and nuclear and perinuclear localization was observed intracellularly.4) The detailed analysis of the expression pattern of WDC146 during spermatogenesis is in progress, with the technical difficulty of fixation of testis applicable for in situ hybrization.5) WD40 domain is known to work as the platform motif as the time of protein-protein interaction. The two-hybrid screening was executed repeatedly to detect interactive protein with WDC146, but not yet succeed.6) Cancer-testis genes are defined as testis-specific genes also expressed in many tumors and tumor cell lines. WDC146 may be classified in them, as tumor cell lines tested all showed moderate expression of WDC146, though some tumors did not.7) The WDC146 gene is mapped at 2q14-21 and consists of 22 exons. Besides the intact mRNA of about 4kb, a chimeric one result from mis-splicing always detected at about 1kb size.8) The promoter region was identified within 0.5kb upstream region of exon 1.